view src/database.c @ 853:2b6fa2618f76

[xemacs-hg @ 2002-05-28 08:44:22 by ben] merge my stderr-proc ws make-docfile.c: Fix places where we forget to check for EOF. code-init.el: Don't use CRLF conversion by default on process output. CMD.EXE and friends work both ways but Cygwin programs don't like the CRs. code-process.el, multicast.el, process.el: Removed. Improvements to call-process-internal: -- allows a buffer to be specified for input and stderr output -- use it on all systems -- implement C-g as documented -- clean up and comment call-process-region uses new call-process facilities; no temp file. remove duplicate funs in process.el. comment exactly how coding systems work and fix various problems. open-multicast-group now does similar coding-system frobbing to open-network-stream. dumped-lisp.el, faces.el, msw-faces.el: Fix some hidden errors due to code not being defined at the right time. xemacs.mak: Add -DSTRICT. ================================================================ ALLOW SEPARATION OF STDOUT AND STDERR IN PROCESSES ================================================================ Standard output and standard error can be processed separately in a process. Each can have its own buffer, its own mark in that buffer, and its filter function. You can specify a separate buffer for stderr in `start-process' to get things started, or use the new primitives: set-process-stderr-buffer process-stderr-buffer process-stderr-mark set-process-stderr-filter process-stderr-filter Also, process-send-region takes a 4th optional arg, a buffer. Currently always uses a pipe() under Unix to read the error output. (#### Would a PTY be better?) sysdep.h, sysproc.h, unexfreebsd.c, unexsunos4.c, nt.c, emacs.c, callproc.c, symsinit.h, sysdep.c, Makefile.in.in, process-unix.c: Delete callproc.c. Move child_setup() to process-unix.c. wait_for_termination() now only needed on a few really old systems. console-msw.h, event-Xt.c, event-msw.c, event-stream.c, event-tty.c, event-unixoid.c, events.h, process-nt.c, process-unix.c, process.c, process.h, procimpl.h: Rewrite the process methods to handle a separate channel for error input. Create Lstreams for reading in the error channel. Many process methods need change. In general the changes are fairly clear as they involve duplicating what's used for reading the normal stdout and changing for stderr -- although tedious, as such changes are required throughout the entire process code. Rewrote the code that reads process output to do two loops, one for stdout and one for stderr. gpmevent.c, tooltalk.c: set_process_filter takes an argument for stderr. ================================================================ NEW ERROR-TRAPPING MECHANISM ================================================================ Totally rewrite error trapping code to be unified and support more features. Basic function is call_trapping_problems(), which lets you specify, by means of flags, what sorts of problems you want trapped. these can include -- quit -- errors -- throws past the function -- creation of "display objects" (e.g. buffers) -- deletion of already-existing "display objects" (e.g. buffers) -- modification of already-existing buffers -- entering the debugger -- gc -- errors->warnings (ala suspended errors) etc. All other error funs rewritten in terms of this one. Various older mechanisms removed or rewritten. window.c, insdel.c, console.c, buffer.c, device.c, frame.c: When creating a display object, added call to note_object_created(), for use with trapping_problems mechanism. When deleting, call check_allowed_operation() and note_object deleted(). The trapping-problems code records the objects created since the call-trapping-problems began. Those objects can be deleted, but none others (i.e. previously existing ones). bytecode.c, cmdloop.c: internal_catch takes another arg. eval.c: Add long comments describing the "five lists" used to maintain state (backtrace, gcpro, specbind, etc.) in the Lisp engine. backtrace.h, eval.c: Implement trapping-problems mechanism, eliminate old mechanisms or redo in terms of new one. frame.c, gutter.c: Flush out the concept of "critical display section", defined by the in_display() var. Use an internal_bind() to get it reset, rather than just doing it at end, because there may be a non-local exit. event-msw.c, event-stream.c, console-msw.h, device.c, dialog-msw.c, frame.c, frame.h, intl.c, toolbar.c, menubar-msw.c, redisplay.c, alloc.c, menubar-x.c: Make use of new trapping-errors stuff and rewrite code based on old mechanisms. glyphs-widget.c, redisplay.h: Protect calling Lisp in redisplay. insdel.c: Protect hooks against deleting existing buffers. frame-msw.c: Use EQ, not EQUAL in hash tables whose keys are just numbers. Otherwise we run into stickiness in redisplay because internal_equal() can QUIT. ================================================================ SIGNAL, C-G CHANGES ================================================================ Here we change the way that C-g interacts with event reading. The idea is that a C-g occurring while we're reading a user event should be read as C-g, but elsewhere should be a QUIT. The former code did all sorts of bizarreness -- requiring that no QUIT occurs anywhere in event-reading code (impossible to enforce given the stuff called or Lisp code invoked), and having some weird system involving enqueue/dequeue of a C-g and interaction with Vquit_flag -- and it didn't work. Now, we simply enclose all code where we want C-g read as an event with {begin/end}_dont_check_for_quit(). This completely turns off the mechanism that checks (and may remove or alter) C-g in the read-ahead queues, so we just get the C-g normal. Signal.c documents this very carefully. cmdloop.c: Correct use of dont_check_for_quit to new scheme, remove old out-of-date comments. event-stream.c: Fix C-g handling to actually work. device-x.c: Disable quit checking when err out. signal.c: Cleanup. Add large descriptive comment. process-unix.c, process-nt.c, sysdep.c: Use QUIT instead of REALLY_QUIT. It's not necessary to use REALLY_QUIT and just confuses the issue. lisp.h: Comment quit handlers. ================================================================ CONS CHANGES ================================================================ free_cons() now takes a Lisp_Object not the result of XCONS(). car and cdr have been renamed so that they don't get used directly; go through XCAR(), XCDR() instead. alloc.c, dired.c, editfns.c, emodules.c, fns.c, glyphs-msw.c, glyphs-x.c, glyphs.c, keymap.c, minibuf.c, search.c, eval.c, lread.c, lisp.h: Correct free_cons calling convention: now takes Lisp_Object, not Lisp_Cons chartab.c: Eliminate direct use of ->car, ->cdr, should be black box. callint.c: Rewrote using EXTERNAL_LIST_LOOP to avoid use of Lisp_Cons. ================================================================ USE INTERNAL-BIND-* ================================================================ eval.c: Cleanups of these funs. alloc.c, fileio.c, undo.c, specifier.c, text.c, profile.c, lread.c, redisplay.c, menubar-x.c, macros.c: Rewrote to use internal_bind_int() and internal_bind_lisp_object() in place of whatever varied and cumbersome mechanisms were formerly there. ================================================================ SPECBIND SANITY ================================================================ backtrace.h: - Improved comments backtrace.h, bytecode.c, eval.c: Add new mechanism check_specbind_stack_sanity() for sanity checking code each time the catchlist or specbind stack change. Removed older prototype of same mechanism. ================================================================ MISC ================================================================ lisp.h, insdel.c, window.c, device.c, console.c, buffer.c: Fleshed out authorship. device-msw.c: Correct bad Unicode-ization. print.c: Be more careful when not initialized or in fatal error handling. search.c: Eliminate running_asynch_code, an FSF holdover. alloc.c: Added comments about gc-cons-threshold. dialog-x.c: Use begin_gc_forbidden() around code to build up a widget value tree, like in menubar-x.c. gui.c: Use Qunbound not Qnil as the default for gethash. lisp-disunion.h, lisp-union.h: Added warnings on use of VOID_TO_LISP(). lisp.h: Use ERROR_CHECK_STRUCTURES to turn on ERROR_CHECK_TRAPPING_PROBLEMS and ERROR_CHECK_TYPECHECK lisp.h: Add assert_with_message. lisp.h: Add macros for gcproing entire arrays. (You could do this before but it required manual twiddling the gcpro structure.) lisp.h: Add prototypes for new functions defined elsewhere.
author ben
date Tue, 28 May 2002 08:45:36 +0000
parents e38acbeb1cae
children c925bacdda60
line wrap: on
line source

/* Database access routines
   Copyright (C) 1996, William M. Perry
   Copyright (C) 2001, 2002 Ben Wing.

This file is part of XEmacs.

XEmacs is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 2, or (at your option) any
later version.

XEmacs is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License
along with XEmacs; see the file COPYING.  If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

/* Synched up with: Not in FSF. */

/* Written by Bill Perry */
/* Substantially rewritten by Martin Buchholz */
/* db 2.x support added by Andreas Jaeger */
/* Mule-ized 6-22-00 Ben Wing */

#include <config.h>
#include "lisp.h"

#include "sysfile.h"
#include "buffer.h"

#ifndef HAVE_DATABASE
#error HAVE_DATABASE not defined!!
#endif

#include "database.h"         /* Our include file */

#ifdef HAVE_BERKELEY_DB
/* Work around Berkeley DB's use of int types which are defined
   slightly differently in the not quite yet standard <inttypes.h>.
   See db.h for details of why we're resorting to this... */
/* glibc 2.1 doesn't have this problem with DB 2.x */
#if !(defined __GLIBC__ && __GLIBC_MINOR__ >= 1)
#ifdef HAVE_INTTYPES_H
#define __BIT_TYPES_DEFINED__
#include <inttypes.h>
typedef uint8_t  u_int8_t;
typedef uint16_t u_int16_t;
typedef uint32_t u_int32_t;
#ifdef WE_DONT_NEED_QUADS
typedef uint64_t u_int64_t;
#endif /* WE_DONT_NEED_QUADS */
#endif /* HAVE_INTTYPES_H */
#endif /* !(defined __GLIBC__ && __GLIBC_MINOR__ >= 1) */
#include DB_H_FILE              /* Berkeley db's header file */
#ifndef DB_VERSION_MAJOR
# define DB_VERSION_MAJOR 1
#endif /* DB_VERSION_MAJOR */
Lisp_Object Qberkeley_db;
Lisp_Object Qhash, Qbtree, Qrecno, Qunknown;
#if DB_VERSION_MAJOR > 2
Lisp_Object Qqueue;
#endif 
#endif /* HAVE_BERKELEY_DB */

#ifdef HAVE_DBM
#include <ndbm.h>
Lisp_Object Qdbm;
#endif /* HAVE_DBM */

Lisp_Object Vdatabase_coding_system;

Lisp_Object Qdatabasep;

typedef struct
{
  Lisp_Object (*get_subtype) (Lisp_Database *);
  Lisp_Object (*get_type) (Lisp_Database *);
  Lisp_Object (*get) (Lisp_Database *, Lisp_Object);
  int (*put) (Lisp_Database *, Lisp_Object, Lisp_Object, Lisp_Object);
  int (*rem) (Lisp_Database *, Lisp_Object);
  void (*map) (Lisp_Database *, Lisp_Object);
  void (*close) (Lisp_Database *);
  Lisp_Object (*last_error) (Lisp_Database *);
} DB_FUNCS;

struct Lisp_Database
{
  struct lcrecord_header header;
  Lisp_Object fname;
  int mode;
  int access_;
  int dberrno;
  int live_p;
#ifdef HAVE_DBM
  DBM *dbm_handle;
#endif
#ifdef HAVE_BERKELEY_DB
  DB *db_handle;
#endif
  DB_FUNCS *funcs;
  Lisp_Object coding_system;
};

#define XDATABASE(x) XRECORD (x, database, Lisp_Database)
#define wrap_database(p) wrap_record (p, database)
#define DATABASEP(x) RECORDP (x, database)
#define CHECK_DATABASE(x) CHECK_RECORD (x, database)
#define CONCHECK_DATABASE(x) CONCHECK_RECORD (x, database)
#define DATABASE_LIVE_P(x) (x->live_p)

#define CHECK_LIVE_DATABASE(db) do {					\
  CHECK_DATABASE (db);							\
  if (!DATABASE_LIVE_P (XDATABASE(db)))					\
    invalid_operation ("Attempting to access closed database", db);	\
} while (0)


static Lisp_Database *
allocate_database (void)
{
  Lisp_Database *db = alloc_lcrecord_type (Lisp_Database, &lrecord_database);

  db->fname = Qnil;
  db->live_p = 0;
#ifdef HAVE_BERKELEY_DB
  db->db_handle = NULL;
#endif
#ifdef HAVE_DBM
  db->dbm_handle = NULL;
#endif
  db->access_ = 0;
  db->mode = 0;
  db->dberrno = 0;
  db->coding_system = Qnil;
  return db;
}

static Lisp_Object
mark_database (Lisp_Object object)
{
  Lisp_Database *db = XDATABASE (object);
  return db->fname;
}

static void
print_database (Lisp_Object obj, Lisp_Object printcharfun, int escapeflag)
{
  Lisp_Database *db = XDATABASE (obj);

  if (print_readably)
    printing_unreadable_object ("#<database 0x%x>", db->header.uid);

  write_fmt_string_lisp (printcharfun, "#<database \"%s\" (%s/%s/",
			 3, db->fname, db->funcs->get_type (db),
			 db->funcs->get_subtype (db));

  write_fmt_string (printcharfun, "%s) 0x%x>",
		    (!DATABASE_LIVE_P (db)    ? "closed"    :
		     (db->access_ & O_WRONLY) ? "writeonly" :
		     (db->access_ & O_RDWR)   ? "readwrite" : "readonly"),
		    db->header.uid);
}

static void
finalize_database (void *header, int for_disksave)
{
  Lisp_Database *db = (Lisp_Database *) header;

  if (for_disksave)
    {
      invalid_operation
	("Can't dump an emacs containing database objects",
	 wrap_database (db));
    }
  db->funcs->close (db);
}

DEFINE_LRECORD_IMPLEMENTATION ("database", database,
                               mark_database, print_database,
			       finalize_database, 0, 0, 0,
			       Lisp_Database);

DEFUN ("close-database", Fclose_database, 1, 1, 0, /*
Close database DATABASE.
*/
       (database))
{
  Lisp_Database *db;
  CHECK_LIVE_DATABASE (database);
  db = XDATABASE (database);
  db->funcs->close (db);
  db->live_p = 0;
  return Qnil;
}

DEFUN ("database-type", Fdatabase_type, 1, 1, 0, /*
Return the type of database DATABASE.
*/
       (database))
{
  CHECK_DATABASE (database);

  return XDATABASE (database)->funcs->get_type (XDATABASE (database));
}

DEFUN ("database-subtype", Fdatabase_subtype, 1, 1, 0, /*
Return the subtype of database DATABASE, if any.
*/
       (database))
{
  CHECK_DATABASE (database);

  return XDATABASE (database)->funcs->get_subtype (XDATABASE (database));
}

DEFUN ("database-live-p", Fdatabase_live_p, 1, 1, 0, /*
Return t if OBJECT is an active database.
*/
       (object))
{
  return DATABASEP (object) && DATABASE_LIVE_P (XDATABASE (object)) ?
    Qt : Qnil;
}

DEFUN ("database-file-name", Fdatabase_file_name, 1, 1, 0, /*
Return the filename associated with the database DATABASE.
*/
       (database))
{
  CHECK_DATABASE (database);

  return XDATABASE (database)->fname;
}

DEFUN ("databasep", Fdatabasep, 1, 1, 0, /*
Return t if OBJECT is a database.
*/
       (object))
{
  return DATABASEP (object) ? Qt : Qnil;
}

#ifdef HAVE_DBM
static void
dbm_map (Lisp_Database *db, Lisp_Object func)
{
  datum keydatum, valdatum;
  Lisp_Object key, val;

  for (keydatum = dbm_firstkey (db->dbm_handle);
       keydatum.dptr != NULL;
       keydatum = dbm_nextkey (db->dbm_handle))
    {
      valdatum = dbm_fetch (db->dbm_handle, keydatum);
      key = make_ext_string (keydatum.dptr, keydatum.dsize,
			     db->coding_system);
      val = make_ext_string (valdatum.dptr, valdatum.dsize,
			     db->coding_system);
      call2 (func, key, val);
    }
}

static Lisp_Object
dbm_get (Lisp_Database *db, Lisp_Object key)
{
  datum keydatum, valdatum;

  TO_EXTERNAL_FORMAT (LISP_STRING, key,
		      ALLOCA, (keydatum.dptr, keydatum.dsize),
		      db->coding_system);
  valdatum = dbm_fetch (db->dbm_handle, keydatum);

  return (valdatum.dptr
	  ? make_ext_string (valdatum.dptr, valdatum.dsize,
			     db->coding_system)
	  : Qnil);
}

static int
dbm_put (Lisp_Database *db,
	 Lisp_Object key, Lisp_Object val, Lisp_Object replace)
{
  datum keydatum, valdatum;

  TO_EXTERNAL_FORMAT (LISP_STRING, val,
		      ALLOCA, (valdatum.dptr, valdatum.dsize),
		      db->coding_system);
  TO_EXTERNAL_FORMAT (LISP_STRING, key,
		      ALLOCA, (keydatum.dptr, keydatum.dsize),
		      db->coding_system);

  return !dbm_store (db->dbm_handle, keydatum, valdatum,
		     NILP (replace) ? DBM_INSERT : DBM_REPLACE);
}

static int
dbm_remove (Lisp_Database *db, Lisp_Object key)
{
  datum keydatum;

  TO_EXTERNAL_FORMAT (LISP_STRING, key,
		      ALLOCA, (keydatum.dptr, keydatum.dsize),
		      db->coding_system);

  return dbm_delete (db->dbm_handle, keydatum);
}

static Lisp_Object
dbm_type (Lisp_Database *db)
{
  return Qdbm;
}

static Lisp_Object
dbm_subtype (Lisp_Database *db)
{
  return Qnil;
}

static Lisp_Object
dbm_lasterr (Lisp_Database *db)
{
  return lisp_strerror (db->dberrno);
}

static void
dbm_closeit (Lisp_Database *db)
{
  if (db->dbm_handle)
    {
      dbm_close (db->dbm_handle);
      db->dbm_handle = NULL;
    }
}

static DB_FUNCS ndbm_func_block =
{
  dbm_subtype,
  dbm_type,
  dbm_get,
  dbm_put,
  dbm_remove,
  dbm_map,
  dbm_closeit,
  dbm_lasterr
};
#endif /* HAVE_DBM */

#ifdef HAVE_BERKELEY_DB
static Lisp_Object
berkdb_type (Lisp_Database *db)
{
  return Qberkeley_db;
}

static Lisp_Object
berkdb_subtype (Lisp_Database *db)
{
  if (!db->db_handle)
    return Qnil;

  switch (db->db_handle->type)
    {
    case DB_BTREE: return Qbtree;
    case DB_HASH:  return Qhash;
    case DB_RECNO: return Qrecno;
#if DB_VERSION_MAJOR > 2
    case DB_QUEUE: return Qqueue;
#endif
    default:       return Qunknown;
    }
}

static Lisp_Object
berkdb_lasterr (Lisp_Database *db)
{
  return lisp_strerror (db->dberrno);
}

static Lisp_Object
berkdb_get (Lisp_Database *db, Lisp_Object key)
{
  DBT keydatum, valdatum;
  int status = 0;

  /* DB Version 2 requires DBT's to be zeroed before use. */
  xzero (keydatum);
  xzero (valdatum);

  TO_EXTERNAL_FORMAT (LISP_STRING, key,
		      ALLOCA, (keydatum.data, keydatum.size),
		      db->coding_system);

#if DB_VERSION_MAJOR == 1
  status = db->db_handle->get (db->db_handle, &keydatum, &valdatum, 0);
#else
  status = db->db_handle->get (db->db_handle, NULL, &keydatum, &valdatum, 0);
#endif /* DB_VERSION_MAJOR */

  if (!status)
    return make_ext_string (valdatum.data, valdatum.size,
			    db->coding_system);

#if DB_VERSION_MAJOR == 1
  db->dberrno = (status == 1) ? -1 : errno;
#else
  db->dberrno = (status < 0) ? -1 : errno;
#endif /* DB_VERSION_MAJOR */

  return Qnil;
}

static int
berkdb_put (Lisp_Database *db,
	    Lisp_Object key,
	    Lisp_Object val,
	    Lisp_Object replace)
{
  DBT keydatum, valdatum;
  int status = 0;

  /* DB Version 2 requires DBT's to be zeroed before use. */
  xzero (keydatum);
  xzero (valdatum);

  TO_EXTERNAL_FORMAT (LISP_STRING, key,
		      ALLOCA, (keydatum.data, keydatum.size),
		      db->coding_system);
  TO_EXTERNAL_FORMAT (LISP_STRING, val,
		      ALLOCA, (valdatum.data, valdatum.size),
		      db->coding_system);
#if DB_VERSION_MAJOR == 1
  status = db->db_handle->put (db->db_handle, &keydatum, &valdatum,
 			       NILP (replace) ? R_NOOVERWRITE : 0);
  db->dberrno = (status == 1) ? -1 : errno;
#else
  status = db->db_handle->put (db->db_handle, NULL, &keydatum, &valdatum,
			       NILP (replace) ? DB_NOOVERWRITE : 0);
  db->dberrno = (status < 0) ? -1 : errno;
#endif/* DV_VERSION_MAJOR = 2 */

  return status;
}

static int
berkdb_remove (Lisp_Database *db, Lisp_Object key)
{
  DBT keydatum;
  int status;

  /* DB Version 2 requires DBT's to be zeroed before use. */
  xzero (keydatum);

  TO_EXTERNAL_FORMAT (LISP_STRING, key,
		      ALLOCA, (keydatum.data, keydatum.size),
		      db->coding_system);

#if DB_VERSION_MAJOR == 1
  status = db->db_handle->del (db->db_handle, &keydatum, 0);
#else
  status = db->db_handle->del (db->db_handle, NULL, &keydatum, 0);
#endif /* DB_VERSION_MAJOR */

  if (!status)
    return 0;

#if DB_VERSION_MAJOR == 1
  db->dberrno = (status == 1) ? -1 : errno;
#else
  db->dberrno = (status < 0) ? -1 : errno;
#endif /* DB_VERSION_MAJOR */

  return 1;
}

static void
berkdb_map (Lisp_Database *db, Lisp_Object func)
{
  DBT keydatum, valdatum;
  Lisp_Object key, val;
  DB *dbp = db->db_handle;
  int status;

  xzero (keydatum);
  xzero (valdatum);

#if DB_VERSION_MAJOR == 1
  for (status = dbp->seq (dbp, &keydatum, &valdatum, R_FIRST);
       status == 0;
       status = dbp->seq (dbp, &keydatum, &valdatum, R_NEXT))
    {
      key = make_ext_string (keydatum.data, keydatum.size,
			     db->coding_system);
      val = make_ext_string (valdatum.data, valdatum.size,
			     db->coding_system);
      call2 (func, key, val);
    }
#else
  {
    DBC *dbcp;

#if DB_VERSION_MAJOR > 2 || DB_VERSION_MINOR >=6
    status = dbp->cursor (dbp, NULL, &dbcp, 0);
#else
    status = dbp->cursor (dbp, NULL, &dbcp);
#endif
    for (status = dbcp->c_get (dbcp, &keydatum, &valdatum, DB_FIRST);
	 status == 0;
	 status = dbcp->c_get (dbcp, &keydatum, &valdatum, DB_NEXT))
      {
	key = make_ext_string (keydatum.data, keydatum.size,
			       db->coding_system);
	val = make_ext_string (valdatum.data, valdatum.size,
			       db->coding_system);
	call2 (func, key, val);
      }
    dbcp->c_close (dbcp);
  }
#endif /* DB_VERSION_MAJOR */
}

static void
berkdb_close (Lisp_Database *db)
{
  if (db->db_handle)
    {
#if DB_VERSION_MAJOR == 1
      db->db_handle->sync  (db->db_handle, 0);
      db->db_handle->close (db->db_handle);
#else
      db->db_handle->sync  (db->db_handle, 0);
      db->db_handle->close (db->db_handle, 0);
#endif /* DB_VERSION_MAJOR */
      db->db_handle = NULL;
    }
}

static DB_FUNCS berk_func_block =
{
  berkdb_subtype,
  berkdb_type,
  berkdb_get,
  berkdb_put,
  berkdb_remove,
  berkdb_map,
  berkdb_close,
  berkdb_lasterr
};
#endif /* HAVE_BERKELEY_DB */

DEFUN ("database-last-error", Fdatabase_last_error, 0, 1, 0, /*
Return the last error associated with DATABASE.
*/
       (database))
{
  if (NILP (database))
    return lisp_strerror (errno);

  CHECK_DATABASE (database);

  return XDATABASE (database)->funcs->last_error (XDATABASE (database));
}

DEFUN ("open-database", Fopen_database, 1, 6, 0, /*
Return a new database object opened on FILE.
Optional arguments TYPE and SUBTYPE specify the database type.
Optional argument ACCESS specifies the access rights, which may be any
combination of 'r' 'w' and '+', for read, write, and creation flags.
Optional argument MODE gives the permissions to use when opening FILE,
and defaults to 0755.
Optional argument CODESYS specifies the coding system used to encode/decode
data passed to/from the database, and defaults to the value of the
variable `database-coding-system'.
*/
       (file, type, subtype, access_, mode, codesys))
{
  /* This function can GC */
  int modemask;
  int accessmask = 0;
  Lisp_Database *db = NULL;
  char *filename;
  struct gcpro gcpro1, gcpro2;

  CHECK_STRING (file);
  GCPRO2 (file, access_);
  file = Fexpand_file_name (file, Qnil);
  UNGCPRO;

  TO_EXTERNAL_FORMAT (LISP_STRING, file,
		      C_STRING_ALLOCA, filename,
		      Qfile_name);

  if (NILP (access_))
    {
      accessmask = O_RDWR | O_CREAT;
    }
  else
    {
      char *acc;
      CHECK_STRING (access_);
      acc = (char *) XSTRING_DATA (access_);

      if (strchr (acc, '+'))
	accessmask |= O_CREAT;

      {
	char *rp = strchr (acc, 'r');
	char *wp = strchr (acc, 'w');
	if (rp && wp) accessmask |= O_RDWR;
	else if (wp)  accessmask |= O_WRONLY;
	else          accessmask |= O_RDONLY;
      }
    }

  if (NILP (mode))
    {
      modemask = 0755;		/* rwxr-xr-x */
    }
  else
    {
      CHECK_INT (mode);
      modemask = XINT (mode);
    }

  if (NILP (codesys))
    codesys = Vdatabase_coding_system;

  codesys = get_coding_system_for_text_file (Vdatabase_coding_system, 1);

#ifdef HAVE_DBM
  if (NILP (type) || EQ (type, Qdbm))
    {
      DBM *dbase = dbm_open (filename, accessmask, modemask);
      if (!dbase)
	return Qnil;

      db = allocate_database ();
      db->dbm_handle = dbase;
      db->funcs = &ndbm_func_block;
      db->coding_system = codesys;
      goto db_done;
    }
#endif /* HAVE_DBM */

#ifdef HAVE_BERKELEY_DB
  if (NILP (type) || EQ (type, Qberkeley_db))
    {
      DBTYPE real_subtype;
      DB *dbase;
#if DB_VERSION_MAJOR != 1
      int status;
#endif

      if (EQ (subtype, Qhash) || NILP (subtype))
	real_subtype = DB_HASH;
      else if (EQ (subtype, Qbtree))
	real_subtype = DB_BTREE;
      else if (EQ (subtype, Qrecno))
	real_subtype = DB_RECNO;
#if DB_VERSION_MAJOR > 2
      else if (EQ (subtype, Qqueue))
	real_subtype = DB_QUEUE;
#endif
      else
	invalid_constant ("Unsupported subtype", subtype);

#if DB_VERSION_MAJOR == 1
      dbase = dbopen (filename, accessmask, modemask, real_subtype, NULL);
      if (!dbase)
	return Qnil;
#else
      /* Berkeley DB Version 2 has only the accessmask DB_CREATE and DB_RDONLY,
	 other flags shouldn't be set */
      if (NILP (access_))
	accessmask = DB_CREATE;
      else
	{
	  char *acc;
	  CHECK_STRING (access_);
	  acc = (char *) XSTRING_DATA (access_);
	  accessmask = 0;

	  if (strchr (acc, '+'))
	    accessmask |= DB_CREATE;

	  if (strchr (acc, 'r') && !strchr (acc, 'w'))
	    accessmask |= DB_RDONLY;
	}
#if DB_VERSION_MAJOR == 2
      status = db_open (filename, real_subtype, accessmask,
			modemask, NULL , NULL, &dbase);
      if (status)
	return Qnil;
#else
      status = db_create (&dbase, NULL, 0);
      if (status)
        return Qnil;
      status = dbase->open (dbase, filename, NULL,
                            real_subtype, accessmask, modemask);
      if (status)
        {
          dbase->close (dbase, 0);
          return Qnil;
        }
#endif /* DB_VERSION_MAJOR > 2 */
      /* Normalize into system specific file modes. Only for printing */
      accessmask = accessmask & DB_RDONLY ? O_RDONLY : O_RDWR;
#endif /* DB_VERSION_MAJOR */

      db = allocate_database ();
      db->db_handle = dbase;
      db->funcs = &berk_func_block;
      db->coding_system = codesys;
      goto db_done;
    }
#endif /* HAVE_BERKELEY_DB */

  invalid_constant ("Unsupported database type", type);
  return Qnil;

 db_done:
  db->live_p = 1;
  db->fname = file;
  db->mode = modemask;
  db->access_ = accessmask;

  return wrap_database (db);
}

DEFUN ("put-database", Fput_database, 3, 4, 0, /*
Store KEY and VALUE in DATABASE.
If optional fourth arg REPLACE is non-nil,
replace any existing entry in the database.
*/
       (key, value, database, replace))
{
  CHECK_LIVE_DATABASE (database);
  CHECK_STRING (key);
  CHECK_STRING (value);
  {
    Lisp_Database *db = XDATABASE (database);
    int status = db->funcs->put (db, key, value, replace);
    return status ? Qt : Qnil;
  }
}

DEFUN ("remove-database", Fremove_database, 2, 2, 0, /*
Remove KEY from DATABASE.
*/
       (key, database))
{
  CHECK_LIVE_DATABASE (database);
  CHECK_STRING (key);
  {
    Lisp_Database *db = XDATABASE (database);
    int status = db->funcs->rem (db, key);
    return status ? Qt : Qnil;
  }
}

DEFUN ("get-database", Fget_database, 2, 3, 0, /*
Return value for KEY in DATABASE.
If there is no corresponding value, return DEFAULT (defaults to nil).
*/
       (key, database, default_))
{
  CHECK_LIVE_DATABASE (database);
  CHECK_STRING (key);
  {
    Lisp_Database *db = XDATABASE (database);
    Lisp_Object retval = db->funcs->get (db, key);
    return NILP (retval) ? default_ : retval;
  }
}

DEFUN ("map-database", Fmapdatabase, 2, 2, 0, /*
Map FUNCTION over entries in DATABASE, calling it with two args,
each key and value in the database.
*/
       (function, database))
{
  CHECK_LIVE_DATABASE (database);

  XDATABASE (database)->funcs->map (XDATABASE (database), function);

  return Qnil;
}

void
syms_of_database (void)
{
  INIT_LRECORD_IMPLEMENTATION (database);

  DEFSYMBOL (Qdatabasep);
#ifdef HAVE_DBM
  DEFSYMBOL (Qdbm);
#endif
#ifdef HAVE_BERKELEY_DB
  DEFSYMBOL (Qberkeley_db);
  DEFSYMBOL (Qhash);
  DEFSYMBOL (Qbtree);
  DEFSYMBOL (Qrecno);
#if DB_VERSION_MAJOR > 2
  DEFSYMBOL (Qqueue);
#endif
  DEFSYMBOL (Qunknown);
#endif

  DEFSUBR (Fopen_database);
  DEFSUBR (Fdatabasep);
  DEFSUBR (Fmapdatabase);
  DEFSUBR (Fput_database);
  DEFSUBR (Fget_database);
  DEFSUBR (Fremove_database);
  DEFSUBR (Fdatabase_type);
  DEFSUBR (Fdatabase_subtype);
  DEFSUBR (Fdatabase_last_error);
  DEFSUBR (Fdatabase_live_p);
  DEFSUBR (Fdatabase_file_name);
  DEFSUBR (Fclose_database);
}

void
vars_of_database (void)
{
#ifdef HAVE_DBM
  Fprovide (Qdbm);
#endif
#ifdef HAVE_BERKELEY_DB
  Fprovide (Qberkeley_db);
#endif

  DEFVAR_LISP ("database-coding-system", &Vdatabase_coding_system /*
Default coding system used to convert data in database files.
*/ );
  Vdatabase_coding_system = Qnative;
}